Hi. On Tue, Feb 4, 2020 at 6:16 AM Arvind Sankar <nivedita@xxxxxxxxxxxx> wrote: > > If the kernel is going to be compressed anyway, there is no point in > double-compressing the built-in initramfs. Hide the built-in initramfs > compression choice in this case. > > Signed-off-by: Arvind Sankar <nivedita@xxxxxxxxxxxx> Double-compression slightly reduces the data size. And, keeping the bare vmlinux small is beneficial, IMHO. > --- > init/Kconfig | 9 +++++++++ > usr/Kconfig | 2 +- > 2 files changed, 10 insertions(+), 1 deletion(-) > > diff --git a/init/Kconfig b/init/Kconfig > index 24b23d843df1..88da0976bbfa 100644 > --- a/init/Kconfig > +++ b/init/Kconfig > @@ -176,6 +176,9 @@ config HAVE_KERNEL_LZ4 > config HAVE_KERNEL_UNCOMPRESSED > bool > > +config KERNEL_COMPRESSED > + bool > + > choice > prompt "Kernel compression mode" > default KERNEL_GZIP > @@ -201,6 +204,7 @@ choice > config KERNEL_GZIP > bool "Gzip" > depends on HAVE_KERNEL_GZIP > + select KERNEL_COMPRESSED > help > The old and tried gzip compression. It provides a good balance > between compression ratio and decompression speed. > @@ -208,6 +212,7 @@ config KERNEL_GZIP > config KERNEL_BZIP2 > bool "Bzip2" > depends on HAVE_KERNEL_BZIP2 > + select KERNEL_COMPRESSED > help > Its compression ratio and speed is intermediate. > Decompression speed is slowest among the choices. The kernel > @@ -218,6 +223,7 @@ config KERNEL_BZIP2 > config KERNEL_LZMA > bool "LZMA" > depends on HAVE_KERNEL_LZMA > + select KERNEL_COMPRESSED > help > This compression algorithm's ratio is best. Decompression speed > is between gzip and bzip2. Compression is slowest. > @@ -226,6 +232,7 @@ config KERNEL_LZMA > config KERNEL_XZ > bool "XZ" > depends on HAVE_KERNEL_XZ > + select KERNEL_COMPRESSED > help > XZ uses the LZMA2 algorithm and instruction set specific > BCJ filters which can improve compression ratio of executable > @@ -241,6 +248,7 @@ config KERNEL_XZ > config KERNEL_LZO > bool "LZO" > depends on HAVE_KERNEL_LZO > + select KERNEL_COMPRESSED > help > Its compression ratio is the poorest among the choices. The kernel > size is about 10% bigger than gzip; however its speed > @@ -249,6 +257,7 @@ config KERNEL_LZO > config KERNEL_LZ4 > bool "LZ4" > depends on HAVE_KERNEL_LZ4 > + select KERNEL_COMPRESSED > help > LZ4 is an LZ77-type compressor with a fixed, byte-oriented encoding. > A preliminary version of LZ4 de/compression tool is available at > diff --git a/usr/Kconfig b/usr/Kconfig > index bdf5bbd40727..f39eeb9ea2e3 100644 > --- a/usr/Kconfig > +++ b/usr/Kconfig > @@ -102,7 +102,7 @@ config RD_LZ4 > > choice > prompt "Built-in initramfs compression mode" > - depends on INITRAMFS_SOURCE != "" > + depends on INITRAMFS_SOURCE != "" && !KERNEL_COMPRESSED > help > This option allows you to decide by which algorithm the builtin > initramfs will be compressed. Several compression algorithms are > -- > 2.24.1 > -- Best Regards Masahiro Yamada
